The editor wishes to express his gratitude to a number of institutions and persons who helped and supported him.

The University Library Duisburg-Essen provided us with the technical infrastructure for this online edition. I am especially grateful to Frank Lützenkirchen who constructed and organized it.

The Deutsche Forschungsgemeinschaft DFG (German Research Foundation) supported this project though a financial grant for three years.

A first version of the application for the project was developed and written by Dr. Sonia Abun-Nasr.

Dr. Sabine Voßkamp worked on the project during the time of the financial support through the DFG. She searched for the material in different archives she visited. She took photographs of the letters or asked for them to be photographed. She also began with the transcription of major parts of the comprehensive collections from the National Archives, the Research Library in Gotha and the State Archives in Hamburg.

A number of people helped me to read letters in foreign and ancient languages:
Aicha Ben Brahim, Svenja Budiak, Prof. Dr. Justus Cobet, Dr. Bettina Marx, Dr. Gabriel Miller, Simone Mura, Ursula Philippi, PD Dr. Astrid Windus und Prof. Dr. Stephanie Zehnle.

Last but not least I have to thank the following archives and libraries who gave permission to include letters in their custody in this edition: